JPS5844715A - Forming method for minute pattern - Google Patents

Abstract

PURPOSE:To form the patterns having high accuracy to both upper and lower layers by specifically treating a resist etching the upper layer when the layer to be etched of the two upper and lower layers is etched. CONSTITUTION:A poly Si layer is deposited onto a Si substrate, an oxide film is shaped to the surface, and a poly Si layr is further formed onto the oxide film. A positive resist is spin-coated onto the poly Si layer, and the resist pattern is shaped through baking, exposure, development, washing and post baking. A substance consisting of acidic phenol resin reacting and combining with hexamethyldisilazane is used as the positive resist. The pattern of the poly Si layer of the upper layer is shaped by the resist pattern. The hexamethyldisilazane is impregnated to the positive resist and the resist pattern is reinforced through baking. A positive resist pattern is formed onto the pattern, and the poly Si layer of the lower layer is etched by the positive resist pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fine pattern pattern forming method for forming two resist pattern patterns with high accuracy in order to etch two upper and lower ψ pattern layers provided on a substrate. .

In general, the method for forming resist turns is to spin-code the resist, bake it to evaporate the solvent from the resist, solidify it, expose it to ultraviolet light to form an image, and form a d-turn with the current solution. It is further strengthened by I-strength baking and improves the adhesion to the substrate.

Now, in some cases, a two-layer OV system is required to perform etching of the upper and lower two layers to be etched.
If you spin code 1s2 resist on top of this without applying JIIm, the first resist will dissolve into this and *
Then, strand 2 is exposed to light and further dissolved in 3jl solution and washing solution. When the first resist pattern is changed in this way, there is a drawback that the formation of zero-count turns in the second layer is disturbed.

The object of the present invention is to eliminate the above-mentioned drawbacks.
After exposure, iJL and washing, it is reacted with -sxamethyldisiladene to form a substance that is photosensitive or soluble even after the 20th exposure and washing. -) A first resist pattern is formed by spin-coding the resist, exposing, developing, cleaning and I-st baking according to a conventional method, and Qt! In the process of forming the pattern of the upper layer by performing etching and pronging by turning, after the formation of the first resist/4 turns or after forming the upper layer/g turns, hexamethylzosilane is applied to the first resist. A third baking process is performed in which the densified film is impregnated with dF and heated to a temperature of 110 to 1 SO°C, and then the upper layer to be etched is etched. Feature 11, characterized in that a pattern is formed and then etched using an OA pattern to form a blue turn in the lower layer, can be achieved by the l-turn forming method. / Giredust may be 4I-)renosuto, which is made of an acidic phenolic resin that reacts with alkaline hexamethylnosiladene and bonds with it; for example, Tokyo Ohka Kogyo 10FPRφ
SOO, sh! Ray 1IAZ1350, Hunt made 11P
R-204 etc. can be used. ・As the second resist, the first resist that reacted with hexamethyldisiladene is used because it dissolves in the gloss turn forming process when the second resist is a negative resist. Can not do it. Therefore, a positive resist is used.

The present invention uses the first and second resists and converts the first resist resistor (v) which has been subjected to four-stroke baking by the usual resist pattern forming process 11 to quinamethylzosiladene, For example, after soaking at 25'C, the temperature is 110-150C.

A third baking is preferably carried out at 130° C. to strengthen the first resist pattern and thereby strengthen the second resist pattern.
It is possible to prevent the pattern from being disturbed in the resist nolene forming step. This third baking may be performed before the first etching to form the upper layer of Noreen, i.e. after the normal post-baking, but
It may be done after the first etching.

Next, the present invention will be explained in detail with reference to an example. A 0.5 μm thick silicon layer is deposited on a silicon substrate by CVD.
method, and the surface is oxidized to a thickness of 0.1 μm.
m oxidized gt shadowing and a further 0.5 j thick polysilicon layer was deposited. Positive resist is made by Tokyo Ohka Kogyo 0
FPR 800 was spin-coded at 500 rpm to a thickness of approximately 1.0 mm, grilled at -85°C for 20 minutes, exposed to wavelength 436 arm (D ultraviolet light to form a latent film, and coated with Tokyo Ohka Kogyo Co., Ltd.). Developed with NMD-3, washed with water, and then post-baked at 130°C for 20 minutes. 0 or more is normal processing. A glossy turn of the upper polysilicon layer was formed by glazing with CF4 containing CF4.

Next, in accordance with the present invention, the substrate is immersed in hexamethylnosiladene at a temperature of 25 CO for 40 minutes and pulled up;
The first resist pattern was strengthened by performing aI3 baking at .degree. C. for 20 minutes.

Further, as a second positive resist, 500% of ordinary Tokyo Ohka Kogyo #I 0FPIIφ800 was applied in a conventional manner.
Spin coded with Orpm to a thickness of 104 mm and a temperature of 8 mm.
Gribake at 5°C for 20 minutes, expose to ultraviolet light with a wavelength of 436!1g11 to form an image, and use Tokyo Ohka Kogyo NMD.
-3, washed with water, and post-baked for 20 minutes at *13 oc to form a second/direzost pattern. With this gloss turn, first, the oxide film is etched with acid-based etching solution, and then KO□59! The underlying polysilicon layer was etched and tenderized by CF4 glazing. This makes it possible to form highly accurate mother turns on both the upper and lower layers.9.

Claims (1)

[Claims] 1. On top and bottom two layers of the coating layer, /diresist, which is reacted with 1 hexamethylzosiladene after exposure, development and washing, a second exposure, The first/gylenost, which converts the photosensitive material into a substance that does not dissolve even after development and washing, is spin-coded, and then subjected to conventional methods such as baking, exposure, development, washing and ? In the step of forming the first resist I line by strike baking and etching using this 9 turn to form the upper layer, after the formation of the first resist Δ turn or the upper layer no line, After forming the turns, the first resist is heated to a temperature of 110~110℃ by applying hexamethyldisiladene.
A third period of etching is performed by heating to 150°C, and then the upper layer to be etched is etched. After etching, a second resist pattern is formed by a conventional method using a second resist, and the lower layer to be etched is etched by this Δ turn to form a lower pattern. Features a fine Δ turn formation method.